Decorative and pressure-receiving button and manufacture thereof



IN VEN TOR.

May 22, l956 P. R. ZELL DECORATIVE AND PRESSURE-'RECEIVING BUTTON AND MANUFACTURE THEREOF Filed May 29, 1952 Yare attached to the metal portions.

f'DECoRA'HvEAND PRESSURE-amenable BUT- TON AND MANUFACTURE mannen Parker R. Zell, Los Angeles, Calif. :Application May 29, 1952, Serial Nc. 290,551

6 Claims. (Cl. 1642) VMy invention relates generally to a plastic-metal article taking the general form of a button and suitable for use as a chair slide, push button, decorative button,

Vor similar use wherein the'article serves not only a structural or pressure receiving function, but in some cases -a Vdecorative function as well. This application is a continuation-in-part of my copending applications, Serial-No. 129,736, entitled Furniture Slide, and SelrialNo. 129,737, entitled Furniture Slide and Method 'have the disadvantage that, if constructed of a hard plastic, they are subject to being broken, permanently deformed, or shattered by severe blows or pressure, and if constructed of a' softer, nonbrittle material, they are subject to deformation by which they tend to become separated from vthe metal portion of the article. Also, if the article is to have a decorative function, it is usually necessary to individually and mechanically'polish the plastic portions of the article before or after they Such an operation is expensive and time consuming.

With a general view to overcoming the aforesaid difficulties andproviding additional advantages, it is a major object of the present invention to provide a plastic button-like article of the class described which can Vhe'quickly and readily fabricated from sheet plastic material.

It is another object of the present invention to provide apparatus for fabricating articles as described in the next preceding paragraph.

`It isstill another object to provide a button of the class described which is particularly suitable for use as a chair slide in that it is resiliently deformable to permit self-leveling of the legs of the chair to which it has been attached, and is yet inherently capable of returningV to its original condition, due to a characteristic known as plastic memory or delayed elasticity.

It is still another object of the present invention to provide an article of the class described which can be quickly processed to produce a high gloss appearance United States Patent ICC the'apparatus of Figure 1,taken on the line 2-2lthe're- 1n;

Figure 3 is a perspective view of anarticlefproduoed by the apparatus shown in Figures l and 2;

Figure 4 is an elevational partially sectioned-view of the article of Figure 3 attached to the leg of a-cliair? for use as a chair slide; and v Figures 5 and 6 Vare alternate forms of the article -similar to that Yshown in Figure 3.

VReferring'to'Figures 3 and 4, it will-be seen-'that one presently preferred form of button comprising m'y-'invention consists in a bezel-like cup or base 10 into which is inserted and secured a hemispherical, hollow, plastic dome 11 through which extends Yain-attachment nail or spike 12. The dome 11 is composed of aplastic material originally in sheet form and stretched'into its hemispherical form in order that the inherent stresses in the sa'me when the shape illustrated in Figure 3 will besuch that the dome, if deformed, will tend to return to its hemispherical shape when the deforming force has been removed. The just-described tendency to return to its original shape is quite pronounced in certain plastic materials, of which one is polyvinyl chloride of the following formula.

`Material: Partsy by weight Polyvinyl chloride resin 10 Tricresyl phosphate (plasticizer) `4v to 5 `Such material has a Shore durometer hardness of-bout 90. Substantially less -or substantiallyYmore-"plasticizer than-the amount indicated produces a harderor softer end product and materially reducesthe propertyof-de- -layed elasticity.

It will be realized by thoseV skilled in the art that other plastic materials also possess' the characteristic of plastic memory or delayed elasticity, i. e.,the characteristic-'of tending to return slowly to its original shape'after deforma- -tion forcesare removed.

Since the material of the plastic dome 11 was originally flat, it tends to return to a at condition,th`at is, the -out'er peripheral edges tend to move foutwardly andthus'continuously force themselves snugly into the overhanging walls of the bezel base 10.

Apparatus for punching the-material of the-domell from a sheet, forming it into-the hemispherical-shapefand inserting it into the base cup 10 is villustrated in Figures l and 2. The sheet material from which the plastic domes ll'are formed is indicated at 15 in Figure 1. This sheet material is intermittently vadvanced to the left by a feed roller 16, the sheet 15- sliding along a platen or table'17, and is fed between a punch 18 mounted in the table/17 and an overlying die 19 supported in a xtureZG extending across the sheet 15. Actually there are a plurality of punches arranged and mounted for concurrent operation in conventional manner. A description of Vone punch will suice for the present purposes of disclosing theinvention, however.

The punch 18 is arranged and adapted to move 'upwardly through the die 19, thus punching out a at'disc 11a of the plastic material of the sheet 15, which'disc rests on the upper end of the punch in the position indicated in dotted line at 21 in Figure 1. It will be realized, of course, that the feed roller 16'is momentarily stopped by control means (not shown) during the operation of the punch 18. Such intermittent feed apparatus being well known in the artof punch press design and operation, a further detailed description thereof is deemed unnecessary herein.

With the punch 18 at rest at the top of its stroke,vthe disc 11a of plastic material in the position-21 Vis thereafter formed into its hemispherical "shape by Vthe-'operation of an upwardly moving rami 22 coaxial-ly'positionedwith- V"in the punch 18. The ram 22 is rounded at its upper end described. Since sequentially operating punches and the like are known in the art, it is deemed unnecessary herein 'to describe in detail the mechanisms for moving and synchronizing the punch 18 and the ram 22.

The operation of forming the 'disc 11a into the dome 11 is accomplished by forcing the disc from its position on :top of the punch 18 upwardly through an inwardly fitapered upper bore portion 24 of the die 19. After leavr'ing the die 19, the disc is forced upwardly into an inserting fixture indicated generally at 25, coming to rest in a supporting cup 26, The cup 26 has a central aperture 26a formed therein to clear the perforating spike 23, if the latter is employed.

The inserting fixture is comprised of a plurality of tubular barrels 27, all secured in a transverse rotary supporting drum 28 which is in turn mounted for rotation in journal bearings 29. The transverse axis 30 of the supporting drum 28 is arranged immediately above the vertical axis of the punch and die 18-19 so that successive rotations of the drum 28 move the barrels 27 one after another into alignment with the vertical axis of the punch and die. Successive operational stations of the barrels 27 are designated 27a, 27b and 27e in the drawings. The operational control mechanism (not shown) is so synchronized as to place a successive one of the barrels 27 above the punch and die 18-19 with each stroke of the latter. Within each barrel 27 is slidably supported one of the receiving cups 26, pairs of such cups being secured together by a connecting bar 31 so that upward movement of one of the cups 26 (located at the lower station 27a) as a result of receiving the upwardly moving hemispherically formed disc 11 moves the diametrically opposite cup upwardly to eject the dome 11 from the uppermost barrel 27 (at station 27C). In Figure 2, it will be noted that the connecting bars 31 of two pairs of barrels 27 are laterally offset so as to clear each other. The barrels 27 are formed with internal shoulders as indicated at 32, so as to limit the aforesaid ejecting movement of the cups 26.

The direction of rotation of the supporting drum 28 is anti-clockwise, as viewed in Figure 1, whereby the dome-containing barrel 27 falls in an intermediate hori- :zontal station 27 b at the time the lowermost barrel is positioned at station 27a to receive a dome 11 thrust upwardly by the ram 22. A spike 12 is forced into the dome 11 which is positioned at the intermediate station 27b by a laterally moving magnetized ram 35, which moves reciprocally as indicated by the arrow 36, in synchronism with the intermittent rotation of the drum 28. Spikes 12 are fed down a stripping chute 37 in conventional manner, and one of the spikes 12 is picked up by each stroke of the ram 35, the forward end of which is magnetized so as to support the spike and thrust it outwardly through the perforation in the top of the dome 11. The resiliency of the dome 11 and the fact that it is compressed into the barrel 27 causes it Vto seize the spike 12 and separate the same from the ram 3S when the latter is withdrawn.

Across the top of the fixture 25 is a feed chute 4t) through which a plurality of the bezel bases 10 is fed to the left by gravity feed or other suitable conventional means, a detent (not shown) being provided to catch and releasably hold a base 10 in a position of alignment above the uppermost barrel station 27C. The minimum diameter of the inwardly sloping walls 10a of the base 10 is approximately equal or slightly larger than the internal diameter of the barrel 27. Thus when the dome 11 is ejected upwardly from the barrel 27, it moves into the aligned base 10 and the resiliency of the dome 11 expands it outwardly into the base 10, holding it securely therein. The next successive 90 rotation of the drum 28 carries the finished article 10-11-12 along a curved portion 40a of the track 40, due to the fact that the dome 11 and the spike 12 still remain partially engaged with the cup 26 even after the dome 11 has been inserted into a base 10. As the article moves along the curved track 40a, however, it is gradually withdrawn from the cup 26 and discharged from the chute 40.

In some cases, an alternative form of pressure-receiving button is desired, such as shown in Figure 5, wherein the spike 12a instead of being supported in the dome 11, is supported in a central aperture in the base 10. Such a central aperture in the base 10 may be made slightly smaller than the shank of the spike 12a so that when the latter is driven in, it will be held in place frictionally. Spikes 12a are assembled with bases 10 in conventional fashion prior to feeding the bases 10 along the chute 40. Thus the spikes extend upwardly as indicated in dotted line in Figure l. When articles of the type shown in Figure 5 are assembled with the apparatus shown in Figure l, an alternative type of forming ram 22, having no spike 23 thereon, is employed, and thus the domes 11 are not perforated as they are pressed into place in the cup 26. For similar reasons, the operation of the spike inserting ram 35 is discontinued during the assembly of articles of the type shown in Figure 5.

Buttons of the type shown in Figure 6, wherein the attachment spikes 12b are integrally formed from the material of the base 10 itself, are assembled by the same series of operations as just described in connection with the form shown in Figure 5.

After the articles are discharged from the chute 40a, the dome 11 may be quickly polished by subjecting the same to a gas llame momentarily. Such brief exposure to the heat of a flame fuses a very shallow surface layer of the dome 11, and due to the fact that such surface layer is under tension due to the forming operation above described, the material when thus heated@ spreads and smooths out to form a very high gloss finish, equal or superior to that which can be achieved by forming the same in polished molds, or by polishing it abrasively after it is formed.

The stresses trapped in the dome 11 due to the forming operation and the fact that it is subsequently inserted and held in the base 10, have the additional advantage that the interior or internal portions of the dome are under compression whereas the outer skin is in tension. A dome of this type is much superior to a solid molded dome from the standpoint of resiliency as when used as a chair slide, and also the tendency to return to its hemispherical shape when deformed due to the weight of a chair as shown Vin Figure 4, is enhanced.

The behavior of the dome 11, when subjected to deforming forces, is quite curious. If such forces are applied and released suddenly, as by a hammer blow, the material behaves similarly to rubber, that is, it deform's resiliently and quickly returns to its initial shape. On the other hand, if a force is applied and remains applied over an appreciable period of time, the material first yields resiliently to an amount proportional to the force and thereafter gradually deforms further at a relatively slow rate. When the deforming force is removed, the plastic material does not instantly return completely to its initial shape. Instead it springs back by an amount approximately equal to its initial deformation and there- F after, over an extended period of time, it creeps back toward its original shape. While the polyvinyl chloride material previously described has a tendency to behave in the manner just described when it is in its normal sheet form, such tendency is greatly increased when the material is mechanically preconditioned, that is, formed under pressure and held in its stressed shape as herein described.

The above-described attributes are particularly useful in a chair slide in that if four of the articles are secured to the bottoms of the legs as shown in Figure 4,

several advantages accrue. First of all, if the legs are not exactly vertical but slightly sloped, the chair slides 11-12 can, over a period of time, tilt so as to accommodate themselves to a level surface as indicated by the phantom line in Figure 4. Furthermore, if one of the four legs of a chair is slightly too long or slightly too short, the creep or slow deformation of the material under pressure permits a self-leveling action in that even a relatively small force such as the Weight of a chair, if applied over a long enough period of time, will cause the slow deformation of the plastic in an amount suicient to make up for most small discrepancies in the lengths of chair legs or the surface on which the same rest. Such self-leveling action usually takes a matter of hours, and after the chair has reached a level position in which all four legs bear substantially equally, the buttons or slides additionally serve a cushioning purpose in that they behave resiliently when sudden loads are applied as by a person sitting in the chair.

The rubber-like character of the material when subjected to sudden blows also makes it possible to drive the spike 12a of the article shown in Figure 5 by merely striking the top of the dome 11. Such sudden blow on the dome 11 flattens the same and the force is transmitted to the spike 12a, the latter having a somewhat larger head than the spike 12, whereby to receive the blow without damaging the plastic material of the dome 11. The slide shown in Figure 6 is driven in a similar fashion.

While the plastic-metal article has been described in connection with a specific application as a chair slide or furniture supporting member, it is also useful in other applications such as the bumpers employed to cushion the shock of a closing door, or in ornamental push buttons and other buttons wherein a highly polished, but shatterproof gloss surface is desired. In addition to the glossy finish which is achieved by the process above described, the metal-plastic button members constructed according to the present invention have the advantage that the plastic portion always remains tightly secured in the base 10 whereas similar articles constructed of hard molded plastic tend to become loose and rattle due to shrinkage of the plastic portion.

While the device shown and described is fully capable of achieving the objects and providing the advantages hereinbefore stated, it will be realized that it is capable of some modification without departure from the spirit of the invention. For this reason, I do not mean to be limited to the form shown and described, but rather to the scope of the appended claims.

l claim:

l. A resilient yieldable button comprising: a body of plasticized thermoplastic resin deformed to place a surface layer thereof in tension, said layer being fused and reset to gloss the same; and a rigid base member secured to said body to hold the same in said deformed condition and with said surface layer exposed.

2. A resilient yieldable button comprising: a body of polyvinyl chloride plasticized to a Shore durometer hardness of approximately and deformed to place a surface layer thereof in tension, said layer being fused and reset to gloss the same; and a rigid base member secured to said body to hold the same in said deformed condition and with said surface layer exposed.

3. A resilient yieldable button comprising: a hemisphere of plastic material having the property of delayed elasticity, said hemisphere being cold formed from a ilat disc whereby to internally stress the same; and a rigid base member secured against the flat side of said hemisphere to hold the same in its hemispherical shape against the force of said internal stress.

4. A resilient yieldable button comprising: a hemisphere of polyvinyl chloride resin plasticized with tricresyl phosphate to a Shore durometer hardness of approximately 90, said hemisphere being cold formed from a at disc whereby to internally stress the same; and a rigid base member secured against the flat side of said hemisphere to hold the same in its hemispherical shape against the force of said internal stresses.

5. A resilient yieldable button comprising: a hemispherical body of plastic material having the property of delayed elasticity, said body being prestressed to urge the same to flatten if not restrained and a convex surface of said body being exposed to receive externally applied pressure; and a rigid base member secured to said body to restrain the same against said flattening urged by said prestressing.

6. A resilient yieldable button comprising: a hemisphere of polyvinyl chloride resin plasticized with tricresyl phosphate to a Shore durometer hardness of approximately 90, said hemisphere being cold formed from a iiat disc whereby to internally stress the same; a rigid cup member embracing the margin of said hemisphere to hold the same in said hemispherical shape against the force of said internal stress; and an attachment spike embedded in said hemisphere and extending from the apex thereof.

References Cited in the file of this patent UNITED STATES PATENTS 1,487,678 Gebhard Mar. 18, 1924 1,855,625 Darnell Apr. 26, 1932 1,904,770 Skillman Apr. 18, 1933 2,030,649 Miller Feb. 11, 1936y 2,188,396 Semon Jan. 30, 1940g 2,263,815 Northup et al. Nov. 25, 1941 2,394,881 Stuhlfauth Feb. 12, 1946i 2,551,960 Meyer May 8, 1951 

